Growing up in long Island in the 1960s, writer Mark Zakarin attended more than his share of over-the-top bar mitzvahs, most of them courtesy of his mother, a party planner for a major local banquet hall. "Over the top" in those days, he informed The Report, depended on whether one booked the Viennese dessert table, the flaming dessert, or - holy of holies - the champagne-glass pyramid. "It was show business, spectacle," he recalled. And for people who lived in cookie-cutter neighborhoods, such extravagance offered a chance to eke out a class distinction or two.

Moving to Hollywood, where, most recently, he wrote for such quirky and cutting-edge cable fare as "The L Word," and helped develop programs like "Queer as Folk" and "The Chris Isaak Show," Zakarin, who today is 58, found new cause to reassess his earlier definitions of excess. There, celebrants have been known to book Sunset Boulevard mosh pits, sports stadiums and even theme parks for their simhas, to fly kids from venue to venue in helicopters, and to hire A-List stars like Beyonce or Hilary Duff for the after-dinner entertainment.

At a recent "Rocky"-themed bar mitzvah, for example, a feisty bocher decked out in pugilistic robes bounded into a makeshift boxing ring and delivered a knockout punch to a Dolph Lundgren look-alike paid to take a dive. Local rumor has it that for another Hollywood affair, the bounteous basketball cheerleaders known as the Clipper Girls convened before one 13-year-old and his titillated chums for a group striptease.

Thus when Zakarin began brainstorming his screenplay for "Keeping Up With the Steins," a family-oriented comedy about bar mitzvah bacchanalia in Brentwood, his biggest challenge was coming up with an opening scene featuring a bar mitzvah bash sufficiently outlandish to make those real-life extravaganzas seem like yesterday's news. What he came up with was a Titanic-themed blowout, with the lad being celebrated sailing into the banquet hall lashed DiCaprio-style to the prow of an ersatz Titanic while embracing a Kate Winslet look-alike from the rear, as he declared, "I am the King of the Torah!"

Shortly after he and first-time director Scott Marshall began screening the film to gatherings of American rabbis, however, Zakarin learned from a Pittsburgh newspaper that his satirical imagination had, in fact, come up short. Some five years earlier, according to the article, a local family had thrown a Titanic-themed bar mitzvah, replete with an almost identical nautical grand entrance.

"You just can't make this stuff up," Zakarin told The Report.

This has not prevented "Keeping Up With the Steins" from becoming a huge hit - at least among Jewish clergy. In their production notes, for instance, the filmmakers include a statement from the cantor of Zakarin's present-day synagogue, who announced that the film comes as a refreshing antidote to a scourge of big bar mitzvahs with "an awful lot of 'Bar' and far too little 'Mitzvah.'" And Rabbi Harold Schulweis, arguably Conservative Jewry's leading congregational luminary on the West Coast, felt impelled, after seeing the film, to send out a community-wide e-mail extolling "Steins" as a seminal piece of Jewish filmmaking.

"I want my B'nei Mitzvah and their parents," wrote Schulweis, "to experience in the movie the shock of recognition and to reexamine their plans to celebrate this rite of passage. I plan to make a viewing of this movie part of the process as families in our congregation begin the planning for their own B'nei Mitzvah."

Among wider audiences, however, the reception has been chillier. Opening with a limited 10-city run, "Steins" scraped in a scant $1.2 million in box office receipts during its first 10 days in release. Critics were mixed in their reviews, with pans generally outweighing picks. The LA Weekly credited Marshall with cinematic skills not generally seen within his filmmaking clan (the director is the son of filmmaker Garry Marshall, and nephew of Penny Marshall), while Roger Ebert called it "a fresh and lovable comedy." More typical, however, was the response of The Hollywood Reporter, which lamented that "Marshall opted to pass up something dry and acidic in favor of a big bottle of Manischewitz," while Box Office magazine and others noted that for a comedy, "Keeping Up With the Steins" just wasn't that funny.

"Keeping Up With the Steins" tells the story of Adam Fiedler (Jeremy Spiven), a wealthy Hollywood agent who decides to go mano a mano against a business rival, Arnie Stein, in a bid to see who can throw the most ostentatious bar mitzvah ever attended in Brentwood. Adam's son, Benjamin (Daryl Sabara, of "Spy Kids" acclaim), however, quickly gloms onto the fact that the planned celebration isn't really about him and his coming of age, nor about anything even remotely spiritual.

Dad says he wants to use the event to make a public display of his vast love for his son, notwithstanding that he has generally been unavailable to guide the boy through the everyday minefields of life. His effort is complicated by the unannounced arrival of his own father, Irwin (Garry Marshall), who abandoned Adam and his mother early on due to an inability or unwillingness to lead the conventional life of a breadwinner. Adam deals with the unwelcome intrusion of his father and his hippie girlfriend (Daryl Hannah) by redoubling his efforts to make his son's bar mitzvah the "Best in Show."

Granddad has become wiser with age, however, and with his help, Benjamin learns that the bar mitzvah is not about blowing other people away, but rather about assuming moral responsibility for your own life and decisions. By the end of Act Three, Benjamin has orchestrated a reconciliation between his father and grandfather, and has downscaled the grandiose celebration planned by his parents for a more meaningful and intimate familial gathering.

Though he was weaned on a diet of leftover pot roast brought home by his party-planning mother, Zakarin did not initially think of making his first feature - he shares a producer's credit alongside his writerly credit - about bar mitzvahs.

"One of our only surviving home movies," he told The Report, in a phone conversation, "which I've since transferred to DVD, is of my bar mitzvah. And when I have a relative come to town and we want to see what we were like 40 years ago, I stick that in and look at this frozen moment in time. What seemed 'show-bizzy' then now seems a little archaic, quaint even.

"One day I got a call from my co-producer, A.D. Oppenheim, who told me about some actor he had seen on a talk show recalling his own bar mitzvah. By then, we had raised some money for our first feature. And it occurred to me that I could write a coming-of-age movie about a bar mitzvah, about this artificial moment, that offered a way of looking at what it means to become a man."

After completing the screenplay, Zakarin and Oppenheim went shopping for a director. They eventually settled on the 37-year-old Marshall. Though not Jewish, Marshall had succumbed to a bad case of bar mitzvah envy, growing up in the San Fernando Valley among the progeny of other entertainment-industry professionals.

"I had actually thought about making a bar mitzvah movie," Marshall told The Report. "It's such a nice ritual, with this definitive moment in which you know you are a man. My culture - we were Italian-Americans who grew up kind of Presbyterian - didn't really have that."

Therein, of course, lay the first hurdle for the filmmakers, which is that most Americans do not have bar or bat mitzvahs, and a great many of them do not even know what they are or may entail. Even in the aftermath of "The Passion of the Christ," which proved that audiences were willing to pay money to see a movie with a religious theme, both filmmakers despaired of their chances of convincing a major studio to finance the project.

"The only way we were able to enlist Miramax as a distributor," Marshall told The Report, "was by pitching the project as a Jewish 'My Big Fat Greek Wedding.' The difference was, everybody knew what a wedding is. Not everyone knows what a bar mitzvah is. In fact, I screened an early version of the film for some relatives from Kentucky, and they simply didn't understand the first half-hour of the film. We had to insert a scene in which Benjamin explains the ritual."

Another concern was the possibility that a film about Jewish ostentation might play into the hands of anti-Semites eager to advance a stereotype of Jews as crass materialists with unseemly amounts of money to burn.

"I would submit," said Zakarin, "that this is not a Jewish phenomenon at all. One of the top reality shows on TV is called 'Sweet Sixteen.' It's about these grandiose parties parents throw to show how much they love their daughters, that they are willing to give them all this so that they can feel special.

"This is the urge, which is as misplaced as it is universal. But since I didn't want to advance a Jewish stereotype, or imply that just Jews do this, I gave our protagonist the most competitive, outrageous profession out there, notably Hollywood agentry. There are all kinds of dark motivations for being excessive that can be attributed to that profession."

These "dark motivations" are of especial concern to Rabbi Schulweis, who laments the "garishness, the grotesqueness, the extravagance, the shallowness, competitiveness, commercialism and hedonism" that have become the hallmark of so many bar mitzvahs, not just within Reform and Conservative Judaism, but among the Orthodox too.

"There is this mythic notion," Shulweis told The Report, "that the Orthodox do it more modestly. If you've ever been at an Orthodox wedding or on one of these Passover cruises, you know better. This has to do with economic class, not with denomination or ideology. Whoever does it, it is demeaning and it is trite."

When Schulweis, who is the rabbi of Temple Valley Beth Shalom, in Encino, first saw the film at a local screening, he told actor Larry Miller, whose character, Arnie Stein (Adam's former partner and current rival), begins the movie by feting his son with the Titanic-themed party, that he had been virtually trembling at the prospect that the film would not content itself merely with poking fun at Jewish extravagance. "Actually, I've seen far worse than the caricature bar mitzvah depicted in the film. I've seen bar mitzvah safaris, with camel processions. I've seen people bankrupt themselves to 'keep up with the Steins.'

"What I loved about this film was that it was honest. It holds up a badly needed mirror to people who are absolutely mishuga in their quest to impress other people. It shows a kid who decides that he doesn't want this stuff. He wants a bar mitzvah that is more authentic, simple, knowledgeable and competent. He tells his rabbi (Richard Benjamin), for instance, that he knows his trop [the notes for chanting his Torah portion], but he doesn't understand what he is reading. He doesn't want any part of what's clearly a sham.

"The film is a demonstration of Jewish harata, contrition, and offers a resolution I found uplifting. And I intend to show it to our b'nei and b'not mitzva and their families three years before the event. The movie shows a craving for authenticity within the children, but I think that craving is family wide."

"Keeping Up With the Steins," Schulweis concludes, "offers a representation of the character of Judaism that can only create self-esteem and pride."